An efficient Brønsted acid-catalyzed Friedel-Crafts-type alkylation of arenes with α-aryl diazoacetates has been developed. This protocol enables effective access to various highly functionalized diarylmethane derivatives in moderate to high yields. Moreover, the product of selected diaryl acetate could be transformed to β, β-diaryl substituted γ-butyrolactone.
Palladium-Catalyzed Chemoselective Activation of sp<sup>3</sup> vs sp<sup>2</sup> C–H Bonds: Oxidative Coupling To Form Quaternary Centers
作者:Gang Hong、Pradip D. Nahide、Uday Kumar Neelam、Peter Amadeo、Arjun Vijeta、John M. Curto、Charles E. Hendrick、Kelsey F. VanGelder、Marisa C. Kozlowski
DOI:10.1021/acscatal.9b00091
日期:2019.4.5
activation of alkyl C–H bonds vs arene C–H bonds with Pd(OAc)2 has been found to be generalizable to a number of nucleophilic substrates, allowing the formation of a range of hindered quaternary centers. The substrates share a common mechanistic path wherein Pd(II) initiates an oxidative dimerization. The resultant dimer modifies the palladium catalyst to favor activation of alkyl C–H bonds, in contrast to
Cu-Catalyzed Cross-Dehydrogenative Coupling of Heteroaryl C(sp<sup>2</sup>)–H and Tertiary C(sp<sup>3</sup>)–H Bonds for the Construction of All-Carbon Triaryl Quaternary Centers
A Cu-catalyzed protocol for cross-dehydrogenativecoupling of benzofuranones with quinolines, indoles, carbazoles, and thiophene, which furnishes highly functionalized 3,3-diaryl benzofuranones bearing a three aryl quaternary carbon center at the C3 position in good yields, has been developed. A radical mechanism is proposed.
Catalytic Oxidation of 3-Arylbenzofuran-2(3<i>H</i>)-ones with PCC-H<sub>5</sub>IO<sub>6</sub>: Syntheses of 3-Aryl-3-hydroxy/3-amido-3-arylbenzofuran-2(3<i>H</i>)-ones
作者:Bhaskar B. Dhotare、Mukesh Kumar、Sandip K. Nayak
DOI:10.1021/acs.joc.8b01395
日期:2018.9.7
A pyridinium chlorochromate (PCC)-mediated facile oxidative dimerization of 3-arylbenzofuran-2-ones at ambient temperature was developed which undergo oxidative cleavage to 3-aryl-3-hydroxy-benzofuran-2-ones with PCC at elevated temperatures. Finally, direct oxidation of 3-arylbenzofuran-2-ones to 3-aryl-3-hydroxy-benzofuran-2-ones was realized using a combination of PCC (10 mol %) and 2.0 equiv of
SbCl<sub>3</sub>-catalyzed solvent-free Friedel–Crafts reaction of phenols with mandelic acids to 3-aryl benzofuran-2(3<i>H</i>)-ones: Synthesis of spirocyclic 2,3-dihydrobenzofuran-2-ones
作者:Bhaskar B. Dhotare、Manoj K. Choudhary、Sandip K. Nayak
DOI:10.1080/00397911.2016.1226341
日期:2016.11.1
ABSTRACT A facile, SbCl3-catalyzed, one-pot, tandem Friedel–Crafts/lactonization reaction of phenols and mandelic acids has been developed under solvent-free conditions to afford 3-aryl benzofuran-2(3H)-ones in good to high yields (52–90%). Additionally, the utility of 3-aryl benzofuran-2(3H)-ones is demonstrated by using them as precursors in the synthesis of a new class of spirocyclic benzofuran-2-ones